In the 1994 Oscar-winning movie Forrest Gump, there’s a short scene in which Tom Hanks’s character opens a letter of thanks from Apple after his former military colleague and business partner Lieutenant Dan invested some of the profits from the Bubba Gump Shrimp Company in “some kind of fruit company.”

If Gump was real and if he was still clinging on to his investment today, he could have a staggering 12 million shares in the Cupertino company, worth around $7 billion.

FancyDressCostumes.co.uk decided it would be fun to calculate what that investment in Apple would be worth today, “as a way of illustrating Apple’s extra-ordinary growth.”

How much of the shrimping profits Dan invested exactly isn’t mentioned in the movie, so a notional amount of $100,000 is used for this. Given the success of the Bubba Gump Shrimp Company, that’s certainly a plausible figure, and it would have given the pair around a 3% stake in Apple at the time (1970s).

By 1980, that stake roughly translated into 1,476,460 shares, which would have been worth $43 million at the end of the stock’s first day of trading. When the Forrest Gump novel made its debut in 1986, that figure would have reached $46 million, and would have ballooned again to $91.5 million by the time the film was released in 1994.

That sounds like an incredible sum of money, but it’s hardly anything when you consider what Gump’s shares would be worth today. According to Fancy Dress Costumes:

After accounting for two more stock splits in 2000 and 2005, Forrest & Lieutenant Dan’s holding now stands at 11,811,680 shares. As of today, 2nd July 2012, Apple is trading at $591. That means their initial investment of $100,000 back in 1978 is now worth… $6,980,702,880.